[CanAm]

We often refer to cars being driven at 6/10ths, 7/10ths, ..., 10/10ths. Intuitively, it's useful and makes sense, but I've often wondered how those assessments are actually made. People seem to usually be in the same ballpark when making the assessments, but I've also seen differences of a tenth or more, which suggests that maybe there's too much subjectivity involved.

To attempt to quantify it and make it more objective, we could look at proportionality to lap times. But if a given car has a 10/10ths lap time of say 80 seconds (1:20) at Summit, that would mean 9/10ths is about 88 seconds (1:28) and 8/10ths is about 96 seconds (1:36), and those gaps seem way too big to me.

Another quantitative approach would be look at lateral G force. Since that's proportional to speed squared (for a given radius) in curves, say 100 mph gives 1.0 G; then if 9/10ths means 0.9 G, the corresponding speed would be about 95 mph, and 8/10ths (0.8 G) would correspond to about 89 mph. These speed differences seem more reasonable to me than the lap time differences, but maybe even these speed differences are too large to represent increments of tenths?

We could instead bring in driver effort as a factor. The problem there seems to be that driver ability varies widely, but maybe the assumption could be made that we're referring to an expert driver?

There may not be any official way to assess tenths, but I'd still be interested to hear what y'all think.

[BlackTalon]

My take on it is it has more to do with the driver's ability then the car's capabilities until the driver reaches the 'unconscious competant' level. Many developing drivers have incidents because they were driving above their ability at the time, and not necessarily exceeding the capabilities of the car until the driver's compounding mistakes finally exceeded the car's ability to save them.

[CanAm]

Originally Posted by BlackTalon

My take on it is it has more to do with the driver's ability then the car's capabilities until the driver reaches the 'unconscious competant' level. Many developing drivers have incidents because they were driving above their ability at the time, and not necessarily exceeding the capabilities of the car until the driver's compounding mistakes finally exceeded the car's ability to save them.

Certainly fits what I've seen at the track this season. Plenty of avoidable incidents because drivers were attempting to go faster than their true capabilities. Saw it all run groups, but especially among non-instructors. As the saying goes, 'leave your ego at home'. Seems to me that wrecking a car is a very effective way to ruin the fun. So far, I've had no incidents, and I'm trying hard to keep it that way.

[Lupin..the..3rd]

If you're driving at 10/10ths, you are driving flat out. Think of it as a percentage. For example, 9/10th's = 90%. This is in decimal notation, and metric numbering can be confusing for many. Like when it's 23 degrees C outside. Do you wear shorts or a parka? Standard notation is more widely accepted, so whether you're talking about 8/10's or 8mm, you can use 5/16's instead.

[savowood]

I've always thought of it as more of a logarithmic scale. If I'm driving my lap and I'm absolutely on the edge, nailing every entry and exiting within (or over) a few millimeters of the track out, then I'd consider that 10/10ths. For argument's sake, we'll say that was a 100 second lap. The next step wouldn't be a 90 second lap, rather a tenth or so off of that at 100.1-100.2. Then at 8/10ths, about a second off of that. Then, at 7/10ths, maybe 10 seconds. Beyond that it seems to flatten out in my mind...maybe an inverse log at that point.

That's how it sits in my brain. As you see, opinions vary.

[VaSteve]

Its a nice day, Irfan. Go outside and think about something else.

[CanAm]

Originally Posted by Lupin..the..3rd

If you're driving at 10/10ths, you are driving flat out. Think of it as a percentage. For example, 9/10th's = 90%. This is in decimal notation, and metric numbering can be confusing for many. Like when it's 23 degrees C outside. Do you wear shorts or a parka? Standard notation is more widely accepted, so whether you're talking about 8/10's or 8mm, you can use 5/16's instead.

Seems like there's still the question of percentage of what?

Originally Posted by savowood

I've always thought of it as more of a logarithmic scale. If I'm driving my lap and I'm absolutely on the edge, nailing every entry and exiting within (or over) a few millimeters of the track out, then I'd consider that 10/10ths. For argument's sake, we'll say that was a 100 second lap. The next step wouldn't be a 90 second lap, rather a tenth or so off of that at 100.1-100.2. Then at 8/10ths, about a second off of that. Then, at 7/10ths, maybe 10 seconds. Beyond that it seems to flatten out in my mind...maybe an inverse log at that point.

That's how it sits in my brain. As you see, opinions vary.

I like that way of looking at it. And I think it ties in with level of driver effort (ie, increasing driver effort results in diminishing drop in lap time).

Originally Posted by VaSteve

Its a nice day, Irfan. Go outside and think about something else.

Don't worry, I know what you mean. Will be heading out soon, and going to a comedy show tonight. Have to get some office work done this weekend too, but that's penance for the track time.

[Chopper Dropper]

Any "tenths" is based on drivers ability of what the instructor or driver thinks the student or driver is driving, not related to lap times except for that actual car and those conditions. It is a measure in DE instructor terms of how much the student might be leaving on the table, now go outside and play!!
Dirk

[VaSteve]

Originally Posted by Irfan

Seems like there's still the question of percentage of what?

Your wallet.

[HoodPin]

10/10th's is typically the line delineating between drover (less than) and dumbass (more than).